1. Field of the Invention
The invention relates to a chair, in particular an office chair comprising a pedestal, seat support supported on the pedestal by means of a chair column, which seat support comprises a front seat support element and a rear seat support element interconnected via a pivot axle, a seat supported on the seat support elements, a backrest secured to the rear seat support element and a longitudinally adjustable energy storing device articulated to the seat support elements at a distance from their pivot axle for mutually adjusting the backrest and the seat, a front seat support element being provided with a receptacle for the upper end of the chair column.
2. Background Art
Chairs of this type are known from U.S. Pat. No. 4,200,332. Based on the interaction of the seat support elements, of the seat articulated to these seat support elements, of the backrest secured to the rear seat support element and of the gas spring placed between the seat support elements, chairs of this type have a so-called synchronous mechanism, in which any pivoting of the backrest is accompanied by a pivoting of the seat. Insofar in its inclined position the seat adapts in ergonomical manner to the pivoting position of the backrest in such a manner that when pivoting backwards the backrest by e.g. 10.degree., the rear portion of the seat inclines downwards by approximately 5.degree. about the latter's front edge.
Basically, these known chairs have defined limit angles of inclination of the seat and the backrest, which can be adjusted in common owing to the synchronous mechanism. In this connection it is regarded to be disadvantageous that the seat and the backrest cannot be changed in inclination in particular in their extremely upright working position or in their extremely reclined relaxing position, respectively.